public class Teacher extends Person {
    private String department;
    
    public Teacher(String id, String name, String department) {
        super(id, name);
        this.department = department;
    }
    
    @Override
    public void displayInfo() {
        System.out.println("工号：" + id + "，姓名：" + name + "，院系：" + department);
    }
    
    public String getDepartment() { return department; }
}